Μελέτη των ιστολογικών βλαβών του κερατοειδούς από και τα συστατικά της slime - GLP και LPS

The histopathological changes induced in the cornea of rabbit by Pseudomonas aeruginosa (P.a.) and its components slime-GLP and LPS as well as the clinical aspects of the inducted lesions were studied. Experimental keratitis was induced (a) by a single intracorneal injection of live bacteria of the P.a. prototype strain PAC-IR (20-30 cell/per injection), (b) by a single injection of 100μg slime-GLP and (c) by a single injection of 2μg LPS. Slime-GLP and LPS derived from the same strain (PAC-IR) of P.a. that used to induce keratitis. The injected doses were considerably smaller that the corresponding LD₅₀. Histological studies using light microscopy, transmission and scanning electron microscopy were performed at regular intervals following the injection. Clinically, the keratitis caused by live bacteria and slime-GLP was characterized by rapid development of lesions leading to ulceration; it was quite different from the lesions induced by LPS. By light microscopy the lesions induced by live bacteria and slime-GLP were also similar and significantly different from those observed following the LPS injection. In particular, the lesions of keratitis induced by live bacteria and slime-GLP included: (a) Infiltration of the cornea by inflammatory cells, mainly polymorphonuclear leukocytes (PMN's) within 4-8 hours after the injection. Sixteen to 24 hours from the injection the whole thickness of the cornea was occupied by the infiltrates and multiple small abscesses were noted. (b) Erosions on the epithelial and endothelial layer within 16-24 hours. (c) Marked edema of the stroma. (d) Loss of proteoglycans of the matrix and degradation of collagen, within 16-24 hours. Eight hours following the injection of LPS, mild focal inflammatory reaction was observed. It consisted of small sub-epithelial infiltrates of PMN's that extended into the adjacent anterior stoma (24 hours) where it remained localized. No changes of the epithelium, collagen or endothelium were observed. Electron microscopy basically confirmed the findings of light microscopy. In addition, there was intense secretry and phagocytic activity of the PMN's as well as degradation of collagen. Small particles of amorphous electron-dense material, believed to be related to collagen degradation, were present among the collagen fibers. Conclusions: a) In the case of P.a. keratitis our findings are in accordance with those previously reported. b) The results of our study indicate that the pathogenicity of slime-GLP is most likely mediated by the strong inflammatory reaction induced in the corneal tissue. c) There is no significant difference between the lesions induced by P.a. live cells and by slime-GLP. d) LPS according to our results appears to be a less important injurious factor for the cornea.

Grantor dc:publisher

University of Patras

Year dc:date

1990

Authors dc:creator

• Farmakakis, Nikolaos
• Φαρμακάκης, Νικόλαος

• Γλυκολιποπρωτεΐνη (GLP)
• Ηλεκτρονική μικροσκοπία
• Ιστοπαθολογία
• Λιποπολυσακχαρίτης (LPS)
• Πειραματική κερατίτις
• Cornea
• Experimental keratitis
• GLP
• Pseudomonas aeruginosa
• Slime
• Ιατρική και Επιστήμες Υγείας
• Βασική Ιατρική
• Medical and Health Sciences
• Basic Medicine

Language dc:language

gre

Identifier

10.12681/eadd/1390

OAI identifier oai:identifier

oai:10442/1390